This invention relates in general to testing devices for testing high-speed rotary equipment and particularly to a test unit for testing the effect of baffles on gear windage.
As gears in a geartrain rotate, they create windage. Windage is the frictional resistance of the teeth moving through the fluid containing the gear, whether it is air, liquid or air with a spray of a cooling or lubricating liquid. Windage increases greatly as the peripheral speed increases. For example, with gears that have peripheral speeds between 10,000 and 25,000 feet per minute, the windage can be very significant. Windage creates heat and also consumes power from the power source.
In the past, it was found that baffles can reduce the effect of windage. Typically, a baffle is a bowl-shaped shroud that encloses a substantial portion of the gear. There can be many shapes of baffles, and the spacing between the baffles and the gears can vary greatly. There have not been any good ways to test the efficiency of various baffles relative to each other.
An apparatus is provided for testing windage on high-speed gears. The apparatus includes a case that has a sump. A shaft is rotatably mounted in the case for receiving and rotating a test gear. A power source is optimally coupled to the shaft for driving the shaft. A nozzle is mounted in the case for discharging a liquid onto the gear, which then collects in the sump. A pump is connected to the sump and the nozzle for pumping the liquid from the sump to the nozzle. The case has a wall for mounting a test baffle to it for enclosing at least a portion of the gear to test the efficiency of the baffle on reducing windage on the gear. Various sensors are employed to monitor the power required for rotating the gear as well as the temperature rise.